Elevating scaffold



Jan. 13, 1953 A. SENSENBAUGH 2,625,443

ELEVATING scAFFoLD Inventor Andrew Sensenbaugh Jan. 13, 1953 u A.sENsENBAUGH 2,625,443

I l ELEVATING scAFFoLD Filed sept. 27, 1949 s sheets-sheet 2 Ingmar fAhdres'v: Sensenb/g WWW/HM@ Jan. 13, 1953 A. SENSENBAUGH 2,525,443

ELEVATING scAFFoLD Filed Sept. 27, 1949 3 Sheets-Sheet 3 nimh /a F 6 6 K6g 62 66 Inventor Andrew Sensenaugh Ffg.4. By

Patented Jan. 13, 1953 UNITED STATES PATENT OFFICE ELEVATING SCAFFOLDAndrew Sensenbaugh, Elkhart, Ind.v Application September 27, 19449,Serial No. 117,998

somme., (e1. 304-29.)-

This invention relates generally to scaffol'ds and more particularly tothe type sometimes describedas elevating and collapsible and portable,the platform of the scaffold ybeingl supported upon a lazytong structureoperated Iby* a hydraulic cylinder and piston.

A primary object. of this invention is to' provide a lscaffold which'will be completely safe and steady, while allowing for easy portabilityand quick and easy elevation of the scaiTol-dplatform.

Another object of this invention, ancillary to the preceding objects, isto provide a scaffold in which the base is supported upon caster-s atthe corners of the base, each caster being individually adjustable sothat the base can bev accurately leveled, even though the support forthe base is not a level surface.

Another object of thisl invention is to provide a. scaiold in which aminimum number ofparts', each of reasonably light weight, areoperatively assembled together so that repair andV vreplacement on anyone partis facilitated, without the disassembly of any great portion ofthe scafliold.

Aspeciiicobject, of this invention is to provide guides for thetravelers in the lower po-rtion of the lazytong structure designe-d tominimize frictien and to facilitate the initiation` of the upwardmovement of the lazytong structure and platform, this feature. beingparticularly important when the yplatform is heavily laden with materialand/ or personnel.

A-nother object of this invention, closely allied to the immediatelypreceding object, is to provide an elevating scafold in which theplatform oi this scaffold will not be subjected to undue vibrationsorjerky motion, this feature improving the general efliciency of thescaffold to an importan-t degree.

And a last object t0 be mentioned specifically is to vprovide a scafoldwhich is relatively inexpensive and practicable to manufacture, which isadapted for use under widely varied conditions, Which is extremelyconvenient and safe to use, and which will give generally eflicient anddurable service.

'With these objects definitely in view, this invention resides incertain novel features of construction, combination and arrangement ofelements and portions as will be hereinafter described in detail in thespecification, particularly pointed out in the appended claims, andillustrated in the accompanying drawings which form a material part ofthis application, and in which:

Figure 1 is a side elevational view of the assembled scaffold;

Figure 2 is a horizontal sectional view,v takenl substantially upon theline 2 2 in Figure 1';

Figure S'i's an enlarged fragmentary view showing in some detail theconstruction of a lower portion of the'scafold;

Figure 4 is a lower plan View of the platform;

Figure 5 is a fragmentary plan View of al guide on one ofl the beams ofthe base of the scaffold, with a traveler and parts operativelyassociated therewith shown fragmentarily;

Figurel 6 is a vertical sectional. view', taken silbstantiallyl upon theline 6 6 in Figure 4;A

Figure 7 is an enlarged fragmentary View, in perspective, of two of theIparts hereinafter referred to as bases used in the corner constructionsof the lazytong structure; this figure showing portions of adjacentlazytong bars;

Figure 8 is a vertical sectional view, taken subv-stantially upon theline li-8 of Figure 31, 'with certain portions removed; and

Figure 9 is a fragmentary enlarged view', in

perspective, of a corner of the platform, the

view being taken from the underside of the platform.

Similar characters of' referenceV endeavor to i designate similar oridentical elements andv por- .cylinder Hl disposed verticallyy andsecured t6 radiating horizontal beams l2, illustrated as being v four innumber, and diametrically oppositely disposed with reference tothecylinder lll. Each of the beams l2 is T'shaped in vertical crosssection,A the top liangebeing indicated at Il. The beams I2 aresupported at their outer ends upon caster constructions including hollowcylinders I6 integral with the outer ends of the beams, vertical axialmembers I8 carrying casters 20 on the lower ends thereof, and handwheels 22 secured to the upper ends of threaded .Shanks 24 whcih areprevented from vertical movement within the hollow cylinders I 6 andwhich are .threaded into the axial members I8 to raise and lower thesame with reference to the beams I2, so that the base of the scaiold canbe leveled accurately.

A guide, generally indicated at 28, is rigidly secured to each of thebeams l2, each guide including a vertical web 3U welded or otherwiserigidly secured to the flange I 4 of the corresponding beam, and aninclined smooth 'surfaced rail 32 integral with the upper edge portionof the web 30. A similar number of travelers, generally indicated at 36,are slidably mounted upon the rails 32, each traveler including a shoe38 and a pivot pin 40 disposed horizontally for connection to the outerend of an inflexible link 42, the inner end of this link being pivoted,as indicated at 44, to a bracket carried by the upper end of a piston 46operatively associated with the hydraulic cylinder l0, Figure 3 showinga construction in which links 42 are secured by brackets 44 to a pistonrod 'portion of such a piston, it being understood this detail of theconstruction may be varied according to individual preferment andmechanical expediency.

Each of the travelers 36 is provided with an upstanding flange 48 andthese iianges are used for indirect connection of the travelers withthe,

lazytong structure generally indicated at 50 in Figure 1. The lazytongstructure includes lowermost lazytong bars 52, intermediate lazytongbars 54 operated by the lowermost lazytong bars 52 'f and uppermostlazytong bars 56 operated by the intermediate lazytong bars 54. Verticalsp-acers 58, shown to advantage in Figure 7, are pivlotally vsecured tothe lazytong bars and these spacers have pivot pins provided in pairsand angularly disposed, as :best indicated in Figure 5, so that thelazytong bars are right angularly disposed to each other at each cornerof a square lazytong structure, as will be clear from an inspection ofFigure 2.

The scaffold platform B2 will ordinarily be square and will be supportedat its corner-s on shoes 6B carried by the uppermost spacers 58, as.best illustrated in Figure 6, and slidably mounted on 'guides 68 whichmaybe simple channel members seciu'ed to the under surface of theplatform 82.

The operation of this invention will be clearly understood from aconsideration of the foregoing description of the mechanical detailsthereof taken in connection with the drawings and the above recitedobjects.

In recapitulation, it might be pointed out that upon the subjection ofpressure upon the piston 46 within the cylinder I0, a source ofhydraulic pressure being diagrammatically illustrated at 10, an upwardand inward pull will be exerted on the inflexible links 42, causing thetravelers 36 tovslide along the guides 28 with the resultantcharacteristic action of the lazytong structure 50 and the raising ofthe platform 62. it should be carefully noted that when this action isrst initiated, the pull on the travelers 3B willi-be parallel to therails 32,.thus minimizing the friction; between the travelers and theguides 28 and making it easier for the various elements concerned tostart their movementssmoothly. It

may also be noted that the specific spacers 58 are designed so that theplatform 62 is rigidly supported when the scaffold is in depressedposition. The other objects and advantages already mentioned will al-sobe clearly and amply achieved by this invention, and further descriptionwould appear unnecessary.

Obviously, minor variations from the embodiment described in thespecification and illustrated in the drawings may be resorted to withoutdeparture from the spirit'and scope of this invention, all within the'scope of the appended claims.

Having described the invention, what is claimed as new is:

l. An elevating scaffold comprising a hydraulic cylinder, an even numberof oppositely disposed radiating beams rigidly secured at their innerends to said cylinder and together comprising a base, a guide on each ofsaid beams, a traveler slidably mounted on each guide, a lazytongstructure including lowermost lazytong bars each terminally andpivotally secured to a traveler, intermediate lazytong bars operated bythe lowermost lazytong bars, and uppermost lazytong bars 0perated by theintermediate lazytong bars, a platform, guides on the lower surface 1ofsaid platform and vertically coplanar with said guides onthe beams ofthe base, shoes slidably mounted on the guides on the platform andpivotally secured to said uppermost lazytong bars, a piston operativelymounted in said cylinder, and links operatively connecting said pistonto said travelers, said guides on the beams being inclined upwardlytoward said cylinder, said links being substarrtially parallel with saidguides on the beams when the scaffold is depressed, so that the frictionbe# tween the travelers and the guides on the beams is minimized at thebeginning of the upward extension of the scaffold.

2. A scaiold according to claim l and wherein said lazytong structure ishorizontally square and said beams and the guides thereon are disposeddiagonally of the lazytong structure.

ANDREW SENSENBAUGH.

REFERENCES CITED Ross June 25, 1946

